JP2006127776A - Circuit connection material, connection structure of circuit terminal and connection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit connection material hardly causing warpage as compared with a conventional cation/epoxy-cured system, in low-temperature connection, for instance, at 160&deg;C for 10 sec. <P>SOLUTION: This circuit connection material 4 is interlaid between circuit electrodes 1a and 2a facing each other for electrically connecting the electrodes 1a and 2a by heating and pressing the circuit electrodes 1a and 2a facing each other only in the pressurized direction. The circuit connection material contains the following constituents (1)-(4): (1) a radical polymerizing substance; (2) a polymerization initiator generating an uncombined radical by heating; (3) an epoxy resin; and (4) a cation polymerizing initiator. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a circuit connection material that is interposed between circuit electrodes facing each other, heats and presses the circuit electrodes facing each other, and electrically connects only the electrodes in the pressurizing direction, a circuit terminal connection structure, and a connection method And about.

Epoxy resin adhesives are widely used in various applications such as electricity, electronics, architecture, automobiles and airplanes because of their high adhesive strength and excellent water resistance and heat resistance.
Among them, the one-pack type epoxy resin adhesive is used in the form of a film, a paste, or a powder because it is not necessary to mix the main agent and the curing agent and is easy to use.
However, when an epoxy resin adhesive is used to connect the semiconductor chip to the glass substrate, there is a problem that the glass substrate is warped.

On the other hand, a radical polymerizable adhesive is known as a low-temperature fast-curing adhesive (for example, Patent Document 1). Epoxy resin adhesives and radical polymerization adhesives are usually used separately as different polymerization type adhesives.
WO98 / 44067 brochure

  An object of the present invention is to provide a circuit connecting material with less warpage.

As a result of diligent research in view of the above problems, the present inventors have found that warpage can be reduced by hybrid curing combining a cationic polymerizable epoxy resin adhesive and a radical polymerizable adhesive, and the present invention has been completed. I let you.
According to the present invention, the following circuit connection materials and the like are provided.
1. A circuit connecting material that is interposed between opposing circuit electrodes, heats and presses the opposing circuit electrodes, and electrically connects only the electrodes in the pressing direction, and includes the following components (1) to (4) A circuit connecting material containing.
(1) Radical polymerizable substance (2) Polymerization initiator that generates free radicals upon heating (3) Epoxy resin (4) Cationic polymerizable initiator In DSC measurement in the range of 2.0 ° C to 300 ° C, the exothermic curve 2. The circuit connecting material according to 1, wherein a calorific value of the remaining peaks excluding a peak at which the peak temperature is 200 ° C. or higher is 60% or more of the total calorific value.
In DSC measurement in the range of 3.0 ° C. to 300 ° C., the exothermic start temperature of the remaining peaks excluding the peak where the temperature at the top of the exothermic curve is 200 ° C. or higher is 60 ° C. or higher, and the exothermic end temperature of the peak is 3. The circuit connection material according to 1 or 2, which is 180 ° C. or lower.
4). The radical polymerizable substance (1) is a (meth) acrylate compound, and the (meth) acrylate equivalent of the (meth) acrylate compound is any one of 1 to 3 greater than the epoxy equivalent of the epoxy resin (3). Circuit connection material.
5. 5. The circuit connection material according to 4, wherein the (meth) acrylate compound contains 6 or more ethylene oxide and / or propylene oxide in the skeleton, and has 2 or more (meth) acryloyl groups.
6). The first circuit member having the first connection terminal and the second circuit member having the second connection terminal are arranged to face the first connection terminal and the second connection terminal, and The circuit connection material according to any one of 1 to 5 is interposed between the first connection terminal and the second connection terminal that are arranged to face each other, and only the first connection terminal and the second connection terminal that are arranged to face each other. A circuit terminal connection structure in which is electrically connected.
7). A first circuit member having a first connection terminal and a second circuit member having a second connection terminal are disposed so that the first connection terminal and the second connection terminal are opposed to each other, and the opposed arrangement is performed. The circuit connection material according to any one of 1 to 5 is interposed between the first connection terminal and the second connection terminal, and only the first connection terminal and the second connection terminal that are arranged to face each other by heating and pressing. Circuit terminal connection method for electrically connecting the terminals.

According to the present invention, a circuit connection material with less warpage can be provided.
The circuit connection material of the present invention has less warpage than a conventional cation / epoxy curing system, for example, at a low temperature connection of 160 ° C. for 10 seconds.

The radically polymerizable substance (1) used in the present invention is a substance having a functional group that is polymerized by radicals, and examples thereof include acrylates, methacrylates, and maleimide compounds. The radical polymerizable substance can be used in either a monomer or oligomer state, and the monomer and oligomer can be used in combination. Specific examples of (meth) acrylate include methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, 2-hydroxy-1,3 -Diacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, dicyclopentenyl acrylate, tricyclodecanyl Acrylate, tris (acryloyloxyethyl) isocyanurate and their corresponding methacrylates. Among these, a (meth) acrylate compound containing 6 or more ethylene oxide (EO) and / or propylene oxide (PO) in the skeleton and having 2 or more (meth) acryloyl groups is particularly preferable.
These can be used alone or in combination. If necessary, a polymerization inhibitor such as hydroquinone or methyl ether hydroquinone may be appropriately used.
Moreover, when it has a dicyclopentenyl group and / or a tricyclodecanyl group and / or a triazine ring, since heat resistance improves, it is preferable.

  The maleimide compound contains at least two maleimide groups in the molecule. For example, 1-methyl-2,4-bismaleimidebenzene, N, N′-m-phenylenebismaleimide, N, N′— p-phenylene bismaleimide, N, N′-m-toluylene bismaleimide, N, N′-4,4-biphenylene bismaleimide, N, N′-4,4- (3,3′-dimethyl-biphenylene) Bismaleimide, N, N′-4,4- (3,3′-dimethyldiphenylmethane) bismaleimide, N, N′-4,4- (3,3′-diethyldiphenylmethane) bismaleimide, N, N′- 4,4-diphenylmethane bismaleimide, N, N′-4,4-diphenylpropane bismaleimide, N, N′-4,4-diphenyl ether bismaleimide N, N′-3,3′-diphenylsulfone bismaleimide, 2,2-bis (4- (4-maleimidophenoxy) phenyl) propane, 2,2-bis (3-s-butyl-4-8 (4 -Maleimidophenoxy) phenyl) propane, 1,1-bis (4- (4-maleimidophenoxy) phenyl) decane, 4,4'-cyclohexylidene-bis (1- (4maleimidophenoxy) -2-cyclohexylbenzene, Examples include 2,2-bis (4- (4-maleimidophenoxy) phenyl) hexafluoropropane, etc. These can be used alone or in combination.

  The blending amount of the radical polymerizable substance is preferably 5 to 95 parts by weight, more preferably 10 to 80 parts by weight, and still more preferably 20 to 60 parts by weight with respect to 100 parts by weight of the sum of the epoxy resin and the radical polymerizable substance. .

The polymerization initiator (2) that generates free radicals upon heating used in the present invention is one that decomposes by heating a peroxide compound, an azo compound or the like to generate free radicals. It is appropriately selected depending on the time, pot life, etc. From the viewpoint of high reactivity and pot life, the organic peroxidation has a decomposition temperature of 40 hours or more with a half-life of 10 hours and a decomposition temperature of 180 degrees or less with a half-life of 1 hour. Preferred are organic peroxides having a half-life of 10 hours of decomposition temperature of 60 ° C. or more and a half-life of 1 minute of decomposition temperature of 170 ° C. or less, a half-life of 10 hours of decomposition temperature of 70 ° C. or more, and Most preferred is an organic peroxide having a decomposition temperature of 150 ° C. or less with a half-life of 1 minute.
When the connection time is 10 seconds or less, the blending amount of the curing agent is preferably about 0.5 to 40 parts by weight with respect to 100 parts by weight of the radical polymerizable substance in order to obtain a sufficient reaction rate. -40 parts by weight is more preferred.

The curing agent can be selected from diacyl peroxide, peroxydicarbonate, peroxyester, peroxyketal, dialkyl peroxide, hydroperoxide, silyl peroxide, and the like. Further, in order to suppress corrosion of the connection terminals of the circuit member, the chlorine ions and organic acids contained in the curing agent are preferably 5000 ppm or less, and more preferably less organic acids generated after the thermal decomposition. .
Specifically, it is more preferably selected from peroxyesters, dialkyl peroxides, hydroperoxides, silyl peroxides, and peroxyesters that provide high reactivity.

  Peroxyesters include cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxynoedecanoate, and t-hexyl. Peroxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di (2- Ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, L-hexylperoxy-2-ethylhexanoate, L-butylperoxy-2-ethylhexanoate Nate, t-butylperoxyisobutyrate, 1,1-bis (t-butylperoxy) cyclohexane, -Hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanonate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di (m-toluoyl par Oxy) hexane, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, t-butyl peroxyacetate and the like can be used.

Dialkyl peroxides include α, α′-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, and t-butyl. Cumyl peroxide can be used.
As the hydroperoxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide and the like can be used.

  Diacyl peroxide includes isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinic peroxide, benzoyl Peroxytoluene, benzoyl peroxide, etc. can be used.

  As peroxydicarbonate, di-n-bromoperoxydicarbonate, diisopropylperoxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxymethoxyperoxydicarbonate, (2-Ethylhexylperoxy) dicarbonate, dimethoxybutylperoxydicarbonate, di (3-methyl-3-methoxybutylperoxy) dicarbonate and the like can be used.

  Peroxyketals include 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t- Butylperoxy) -3,3,5-trimethylcyclohexane, 1,1- (t-butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) decane and the like can be used.

Examples of silyl peroxides include t-butyltrimethylsilyl peroxide, bis (t-butyl) dimethylsilyl peroxide, t-butyltrivinylsilyl peroxide, bis (t-butyl) divinylsilyl peroxide, and tris (t-butyl) vinyl. Silyl peroxide, t-butyltriallylsilyl peroxide, bis (t-butyl) diallylsilyl peroxide, tris (t-butyl) allylsilyl peroxide, and the like can be used.
These curing agents that generate free radicals can be used alone or in combination, and a decomposition accelerator, an inhibitor, or the like may be used in combination.

The epoxy resin (3) used in the present invention is typically a bisphenol type epoxy resin derived from epichlorohydrin and bisphenol A, F, D or the like, and an epoxy novolac resin derived from epichlorohydrin and phenol novolac or cresol novolac, In addition, various epoxy compounds having two or more oxirane groups in one molecule such as glycidylamine, glycidyl ester, alicyclic, and heterocyclic can be applied. These can be used alone or in admixture of two or more. For these epoxy resins, it is preferable to use a high-purity product in which impurity ions (Na ⁺ , Cl- ^{and the} like), hydrolyzable chlorine and the like are reduced to 300 ppm or less, in order to prevent electron migration.

  Among the above-mentioned epoxy resins, bisphenol type epoxy resins are preferable because grades having different molecular weights are widely available, and adhesiveness, reactivity, and the like can be arbitrarily set. Among them, the bisphenol F type epoxy resin is particularly preferable because it has a particularly low viscosity and can be set in a wide range of fluidity in combination with a phenoxy resin, or is liquid and easily obtains adhesiveness. A so-called polyfunctional epoxy resin having three or more oxirane groups in one molecule is also preferable because it improves the crosslink density of the composition and improves heat resistance, and occupies the composition in order to maintain repairability with a solvent. The ratio of the polyfunctional epoxy resin can be used as 30% or less.

  The compounding amount of the epoxy resin is preferably 5 to 95 parts by weight, more preferably 20 to 90 parts by weight, and further preferably 40 to 80 parts by weight with respect to 100 parts by weight of the sum of the epoxy resin and the radical polymerizable substance.

  As the cationic polymerizable initiator (4) used in the present invention, onium salts such as aromatic diazonium salts, sulfonium salts, iodonium salts, phosphonium salts, and selenonium salts are preferably used. In particular, the sulfonium salt is suitably used because it has excellent reactivity at low temperatures and has a long pot life. As the sulfonium salt, a sulfonium salt represented by the general formula (1) is preferably used.

一般式（１）中、Ｒ^１はニトロソ基、カルボニル基、カルボキシル基、シアノ基、トリアルキルアンモニウム基、フルオロメチル基、Ｒ^２及びＲ^３はアミノ基、水酸基、メチル基、Ｙ⁻は、ヘキサフルオロアルセネート、ヘキサフルオロアンチモネートである。

In the general formula (1), R ¹ is a nitroso group, a carbonyl group, a carboxyl group, a cyano group, a trialkylammonium group, a fluoromethyl group, R ² and R ³ are an amino group, a hydroxyl group, a methyl group, and Y ⁻ is a hexa Fluoroarsenate, hexafluoroantimonate.

  The blending amount of the sulfonium salt with respect to the epoxy resin is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the epoxy resin. In this case, two or more exothermic peaks may appear due to DSC.

The circuit connection material of the present invention can further contain a thermoplastic resin. As the thermoplastic resin, polyvinyl butyral resin, polyvinyl formal resin, polyamide resin, polyester resin, phenol resin, epoxy resin, phenoxy resin, polystyrene resin, xylene resin, polyurethane resin and the like can be used. In particular, a hydroxyl group-containing resin is preferable because it is excellent in stress relaxation at the time of curing and the adhesion due to the hydroxyl group is improved. A polymer obtained by modifying each polymer with a radically polymerizable functional group is more preferable because heat resistance is improved. In such a case, it is a hydroxyl group-containing resin having a molecular weight of 10,000 or more, and is also a radical polymerizable substance.
The molecular weight of these polymers is preferably 10,000 or more, but if it is 1,000,000 or more, the mixing property tends to deteriorate.

As the hydroxyl group-containing resin, a hydroxyl group-containing resin having a Tg (glass transition temperature) of 40 ° C. or more and a molecular weight of 10,000 or more is preferably used. For example, a phenoxy resin can be used. The hydroxyl group-containing resin may be modified with a carboxyl group-containing elastomer, an epoxy group-containing elastomer, or a radical polymerizable functional group. Those modified with a radically polymerizable functional group are preferred because the heat resistance is improved.
The phenoxy resin can be obtained by reacting a bifunctional phenol and epihalohydrin to a high molecular weight or by polyaddition reaction of a bifunctional epoxy resin and a bifunctional phenol.

  Further, the carboxyl group-containing elastomer and the epoxy group-containing elastomer may be any elastomer as long as it is an elastomer having a carboxyl group or an epoxy group in the molecular terminal or molecular chain, such as a butadiene-based polymer and an acrylic polymer. , Polyether urethane rubber, polyester urethane rubber, polyamide urethane rubber, silicone rubber and the like, and butadiene polymers are preferred. Examples of the butadiene polymer include a butadiene polymer, a butadiene-styrene copolymer, and a butadiene-acrylonitrile copolymer. Of these, butadiene-acrylonitrile copolymers are particularly preferred.

Furthermore, a filler, a softener, an accelerator, an anti-aging agent, a colorant, a flame retardant, a thixotropic agent, a coupling agent, a phenol resin, a melamine resin, isocyanates, and the like can also be contained.
As a coupling agent, a vinyl group, an acrylic group, an amino group, an epoxy group, and an isocyanate group-containing material are preferable from the viewpoint of improving adhesiveness.

Even if the circuit connection material of the present invention does not have conductive particles, connection can be obtained by direct contact of circuit electrodes facing each other at the time of connection. However, when conductive particles are contained, more stable connection can be obtained.
The conductive particles include metal particles such as Au, Ag, Ni, Cu, and solder, and carbon. In order to obtain a sufficient pot life, the surface layer is not a transition metal such as Ni or Cu, but Au, Ag. Platinum group noble metals are preferred, and Au is more preferred.
Further, the surface of a transition metal such as Ni may be coated with a noble metal such as Au. In addition, when the conductive layer described above is formed by coating or the like on non-conductive glass, ceramic, plastic, etc., and the outermost layer is precious metal plastic as the core, or in the case of hot melt metal particles, it is deformable by heating and pressing. Therefore, the contact area with the electrode is increased at the time of connection, and the reliability is improved.

In the circuit connecting material of the present invention, in DSC (differential scanning calorimetry) measurement in the range of 0 ° C. to 300 ° C., the exothermic amount of the remaining peaks excluding the peak at which the temperature at the top of the exothermic curve is 200 ° C. or more is It is preferably 60% or more of the total calorific value.
DSC is based on the zero position method, where the amount of heat is supplied or removed so that the temperature difference from a standard sample that does not generate heat or endotherm is constantly canceled within the measurement temperature range. It can be measured using it.

A method for obtaining the heat generation curve and the heat generation amount will be described below with reference to FIGS. 1 to 4 (calculation examples 1 to 4).
As shown in FIGS. 1 to 4, the heat generation curve is obtained by taking the amount of heat (heat flux) dq / dt supplied per unit time on the vertical axis and the temperature on the horizontal axis. 1 to 4 show a case where the peak A is at 200 ° C. or lower and the peak B is at 200 ° C. or higher in the range of 0 ° C. to 300 ° C. FIG.
The reaction of the adhesive is an exothermic reaction, and when the sample is heated at a constant temperature increase rate, the sample reacts to generate heat. The amount of heat is output to a chart, the area surrounded by the heat generation curve and the base line is obtained with the base line as a reference, and this is defined as the heat generation amount. Measurement is performed from 0 ° C. to 300 ° C. at a rate of temperature increase of 10 ° C./min, and the calorific value described above is obtained. This can be measured fully automatically using a commercially available device.
The ratio of the exothermic amount of the remaining peak (referred to as the residual peak Pr) excluding the peak at which the peak of the DSC is 200 ° C. or higher to the entire DSC peak can be obtained from these area ratios. The remaining peak Pr is indicated by diagonal lines in FIGS. The calorific value (area) ratio (%) of the remaining peak Pr is {A / (A + B)} × 100.
Regarding the heat generation start temperature and heat generation end temperature of the remaining peak Pr, as shown in FIGS. 1 to 4, the temperatures at which the above-described baseline and the heat generation curve of the remaining peak Pr intersect are Ta (heat generation start temperature) and Te (heat generation end temperature). ).
As in Calculation Example 4 shown in FIG. 4, the exothermic curve does not cross the base line, and a so-called shoulder may be created. In this case, the temperature of the portion having the minimum heat flux in the exothermic curve between the peak having a peak at 200 ° C. or higher and the adjacent low-temperature side peak is defined as Te (heat generation end temperature). In addition, the calorific value (area) in calculation example 4 can be obtained from the straight line extending from Te to the exothermic curve, the exothermic curve of the remaining peak Pr, and the area surrounded by the base line.

The calorific value of the remaining peak Pr is preferably 60% or more of the total calorific value, more preferably 75% or more, and further preferably 80% or more. When the heat generation amount of the remaining peak Pr is less than 60% of the total heat generation amount, it takes a long time to complete the curing reaction necessary for circuit connection, which is not preferable because the productivity is inferior.
Moreover, it is preferable that the exothermic start temperature of the remaining peak Pr is 60 ° C. or higher and the exothermic end temperature of the remaining peak Pr is 180 ° C. or lower. When the heat generation starting temperature is lower than 60 ° C., the pot life property is inferior, which is not preferable. Further, if the heat generation end temperature exceeds 180 ° C., a high temperature is required to complete the curing reaction necessary for circuit connection, which is not preferable from the viewpoint of damage to the connection circuit.

  Furthermore, when the radically polymerizable substance (1) is a (meth) acrylate compound, the (meth) acrylate equivalent of the (meth) acrylate compound is more than the epoxy equivalent of the epoxy resin (3). Larger is preferred.

  Further, when the circuit connection material is divided into two or more layers and separated into a layer containing a curing agent and a layer containing conductive particles, an improvement in pot life can be obtained.

In the connection method of the present invention, a first circuit member having a first connection terminal and a second circuit member having a second connection terminal are arranged so that the first connection terminal and the second connection terminal are opposed to each other. The first connection terminal arranged opposite to each other by interposing the connection material (film adhesive) of the present invention between the first connection terminal and the second connection terminal arranged opposite to each other and heated and pressurized And only the second connection terminal is electrically connected.
As such a circuit member, a chip component such as a semiconductor chip, a resistor chip or a capacitor chip, a substrate such as a printed circuit board, or the like is used. The circuit member is usually provided with a large number of connection terminals (or a single connection terminal in some cases).

  In order to obtain better electrical connection, it is preferable that at least one surface of the circuit electrode (connection terminal) is made of a metal selected from gold, silver, tin, and a platinum group. The surface layer is selected from gold, silver, platinum group, or tin, and these may be used in combination. Moreover, it is good also as a multilayer structure combining several metals like copper / nickel / gold.

FIG. 5 is a cross-sectional view illustrating a circuit terminal connection method according to an embodiment of the present invention.
In FIG. 5A, 1 is a first substrate (first circuit member), 2 is a second substrate (second circuit member), and 1a is a first circuit electrode (first connection terminal). 2a is a second circuit electrode (second connection terminal), 3 is an adhesive, 4 is a conductive particle, and 5 is a heating and pressing head. The circuit connection material of the present invention is composed of the adhesive 3 and the conductive particles 4.

The substrates 1 and 2 are insulating substrates such as semiconductor chips such as silicone, gallium and arsenic, glass, ceramics, glass / epoxy composite, and plastic.
The circuit electrode 1a is provided with a copper foil on the surface of the substrate 1, and a gold surface layer is formed thereon. The circuit electrode 2a is provided on the surface of the substrate 2 with a copper foil, and a tin surface layer is formed thereon.
The substrate provided with the circuit electrodes is preferably pre-heated before the connection step using the circuit connection material in order to eliminate the influence on the connection due to the volatile component due to the heating at the time of connection.
As shown in FIG. 5B, after the temporary connection, the circuit electrode 1a of the substrate 1 and the circuit electrode 2a of the substrate 2 are aligned, and the heating and pressing head 5 is heated and pressed for a predetermined time from above the substrate 2. To complete this connection.

Example 1
60 g of bisphenol A / bisphenol F copolymer phenoxy resin (Mw: 65,000) was dissolved in 140 g of ethyl acetate to obtain a 30 wt% solution. By weight, 60 g of bisphenol A / bisphenol F copolymer phenoxy resin, 2.5 g of di-t-butylperoxyhexahydroterephthalate, 10 g of polyethylene glycol diacrylate (average EO number: 23), aromatic sulfonium salt (Sanshin) Made of Chemical Industry, SI-60LA) 2.5g, acrylic rubber fine particle dispersed epoxy resin (BPA328) 30g, silane coupling agent (Toray Dow Corning Silicone, SH-6040) 2.0g, polystyrene core Conductive particles having an Au layer formed on the surface (diameter: 4 μm) were dispersed by 10% by volume to obtain a film coating solution. Next, this solution was applied to a PET (polyethylene terephthalate) film having a surface treated of 50 μm using a coating device, and dried with hot air at 70 ° C. for 10 minutes to obtain a film adhesive having an adhesive layer thickness of 25 μm. It was.

This adhesive was measured by DSC as needed. The residual peak Pr of DSC of this film was 81% of the whole. Further, the heat generation start temperature of the remaining peak Pr was 92 ° C., and the heat generation end temperature was 175 ° C.
After this film adhesive (2 × 20 mm) was attached to a glass substrate with an ITO circuit at 80 ° C. and 1 MPa, the separator was peeled off, and the bumps of the chip and the glass substrate with the ITO circuit were aligned. Next, heating and pressurization were performed from above the chip under the conditions of 160 ° C., 40 g / bump, and 10 seconds to perform the main press bonding. Warpage due to pressure bonding using this film adhesive was 3.0 to 6.0 μm. The connection resistance was 150 mΩ at the maximum per bump and 70 mΩ on the average, and this pressure-bonded body had a constant temperature and humidity treatment of 60 ° C., 90% RH, 300 hours and a maximum of 20 Ω or less, and an average of 5 Ω or less.

The warpage of the glass substrate was determined by the following method. As shown in FIGS. 6A and 6B, an evaluation chip 60 {gold bump (area: 50 × 50 μm, space 20 μm, height 15 μm, number of bumps 362) chip (1.7 × 17 mm, thickness 500 μm) )} And an evaluation glass substrate 62 (thickness 1.1 mm, with ITO wiring) were connected with the obtained adhesive 64 and measured. 6A is a perspective view of the glass substrate 62 with the chip 60 as viewed obliquely from above, and FIG. 6B is a perspective view of the glass substrate 62 with the chip 60 as viewed from obliquely below. When calculating | requiring the curvature of the glass substrate 62, the curvature amount was measured before and behind crimping using the surface roughness meter, and the variation | change_quantity was made into "the curvature by crimping". Further, the warpage was measured by measuring the surface opposite to the side to which the adhesive 64 is pressure-bonded at a distance of 25 mm around the pressure-bonding portion. The positive or negative value of the amount of warpage was defined as a positive warp on the glass side.

(Example 2)
60 g of bisphenol A / bisphenol F copolymer phenoxy resin (Mw: 65,000) was dissolved in 140 g of ethyl acetate to obtain a 30 wt% solution. By weight ratio, 60 g of phenoxy resin, 3.5 g of 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, 10 g of ethoxylated glycerin triacrylate (average EO number: 20), aromatic sulfonium 2.5 g of salt (manufactured by Sanshin Chemical Co., Ltd., SI-60LA), 30 g of acrylic rubber fine particle dispersed epoxy resin (BPA328), 2.0 g of silane coupling agent (manufactured by Toray Dow Corning Silicone, SH-6040), Conductive particles having an Au layer formed on the surface of a polystyrene core (diameter: 4 μm) were dispersed by 10% by volume to obtain a film coating solution. Thereafter, a film adhesive was obtained in the same manner as in Example 1.

This adhesive was measured by DSC as needed. The residual peak Pr of DSC of this film was 84% of the whole. The exothermic start temperature of the remaining peak Pr was 84 ° C., and the exothermic end temperature was 170 ° C.
After this film adhesive (2 × 20 mm) was attached to a glass substrate with an ITO circuit at 80 ° C. and 1 MPa, the separator was peeled off, and the bumps of the chip and the glass substrate with the ITO circuit were aligned. Next, heating and pressurization were performed from above the chip under the conditions of 160 ° C., 40 g / bump, and 10 seconds to perform the main press bonding. Warpage due to pressure bonding using this film adhesive was 3.5 to 6.5 μm. Further, the connection resistance was 110 mΩ at the maximum per bump and 60 mΩ on the average, and this pressure-bonded body had a constant temperature and humidity treatment at 60 ° C. and 90% RH for 300 hours, and the maximum was 20 Ω or less and the average was 5 Ω or less.

(Experimental example 3)
60 g of bisphenol A / bisphenol F copolymer phenoxy resin (Mw: 65,000) was dissolved in 140 g of ethyl acetate to obtain a 30 wt% solution. By weight ratio, bisphenol A / bisphenol F copolymer phenoxy resin 60 g, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane 3.5 g, polyethylene glycol diacrylate (average EO number: 4) 10 g, aromatic sulfonium salt (manufactured by Sanshin Chemical Industry, SI-60LA) 2.5 g, bisphenol A type epoxy resin (epoxy equivalent: 180-190), silane coupling agent (manufactured by Toray Dow Corning Silicone, SH −6040) 2.0 g was blended, and 10% by volume of conductive particles in which an Au layer was formed on the surface of a polystyrene core (diameter: 4 μm) was dispersed to obtain a film coating solution. Thereafter, a film adhesive was obtained in the same manner as in Example 1.

This adhesive was measured by DSC as needed. The residual peak Pr of DSC of this film was 82% of the whole. Further, the heat generation start temperature of the remaining peak Pr was 84 ° C., and the heat generation end temperature was 165 ° C.
After this film adhesive (2 × 20 mm) was attached to a glass substrate with an ITO circuit at 80 ° C. and 1 MPa, the separator was peeled off, and the bumps of the chip and the glass substrate with the ITO circuit were aligned. Next, heating and pressurization were performed from above the chip under the conditions of 160 ° C., 40 g / bump, and 10 seconds to perform the main press bonding. Warpage due to pressure bonding using this film adhesive was 4.5 to 6.5 μm. Further, the connection resistance was 110 mΩ at the maximum per bump and 60 mΩ on the average, and this pressure-bonded body had a constant temperature and humidity treatment at 60 ° C. and 90% RH for 300 hours, and the maximum was 20 Ω or less and the average was 5 Ω or less.

(Comparative Example 1)
90 g of bisphenol A / bisphenol F copolymer phenoxy resin (Mw: 65,000) was dissolved in 210 g of ethyl acetate to obtain a 30 wt% solution. By weight, 67 g of bisphenol A / bisphenol F copolymer phenoxy resin (Mw: 65,000), 2.5 g of aromatic sulfonium salt (manufactured by Sanshin Chemical Industry, SI-60LA), acrylic rubber fine particle dispersed epoxy resin ( BPA 328) 33 g and silane coupling agent (Toray Dow Corning Silicone, SH-6040) 2.0 g were blended, and 10% by volume of conductive particles in which an Au layer was formed on the surface of a polystyrene core (diameter: 4 μm) Thus, a film coating solution was obtained. Thereafter, a film adhesive was obtained in the same manner as in Example 1.

This adhesive was measured by DSC as needed. The DSC residual peak Pr of this film was 72% of the total. Further, the heat generation start temperature of the remaining peak Pr was 90 ° C., and the heat generation end temperature was 150 ° C.
After this film adhesive (2 × 20 mm) was attached to a glass substrate with an ITO circuit at 80 ° C. and 1 MPa, the separator was peeled off, and the bumps of the chip and the glass substrate with the ITO circuit were aligned. Next, heating and pressurization were performed from above the chip under the conditions of 160 ° C., 40 g / bump, and 10 seconds to perform the main press bonding. Warpage due to pressure bonding using this film adhesive was 7.5 to 10.5 μm. The pressure-bonded body had a constant temperature and humidity treatment of 60 ° C., 90% RH, 300 hours and a maximum of 15Ω or less, and an average of 4Ω or less.

(Comparative Example 2)
40 g of bisphenol A type phenoxy resin (Mw: 45,000) was dissolved in 93.3 g of ethyl acetate to obtain a 30 wt% solution. By weight, bisphenol A type phenoxy resin 60g, aromatic sulfonium salt (manufactured by Sanshin Chemical Industry, SI-60LA) 2.0g, acrylic rubber fine particle dispersed epoxy resin (BPA328) 40g, silane coupling agent (Toray Dow Corning) Silicone (SH-6040) 2.0 g was blended, and 10 vol% of conductive particles having an Au layer formed on the surface of a polystyrene core (diameter: 4 μm) were dispersed to obtain a film coating solution. Thereafter, a film adhesive was obtained in the same manner as in Example 1.

This adhesive was measured by DSC as needed. The DSC residual peak Pr of this film was 43% of the total. Further, the heat generation start temperature of the remaining peak Pr was 96 ° C., and the heat generation end temperature was 149 ° C.
After this film adhesive (2 × 20 mm) was attached to a glass substrate with an ITO circuit at 80 ° C. and 1 MPa, the separator was peeled off, and the bumps of the chip and the glass substrate with the ITO circuit were aligned. Next, heating and pressurization were performed from above the chip under the conditions of 160 ° C., 40 g / bump, and 10 seconds to perform the main press bonding. Warpage due to pressure bonding using this film adhesive was 3.0 to 6.0 μm. In addition, the connection resistance was 110 mΩ at maximum per bump and 60 mΩ on average, and this pressure-bonded body was poor in conduction after being treated at a constant temperature and humidity treatment of 60 ° C. and 90% RH for 300 hours.

  The circuit connection material of the present invention can be widely used as an isotropic and anisotropic adhesive for electric and electronic use.

It is a figure for demonstrating the calculation method (calculation example 1) of the emitted-heat amount, the heat-generation start temperature, and the heat-generation end temperature. It is a figure for demonstrating the calculation method (calculation example 2) of the emitted-heat amount, the heat-generation start temperature, and the heat-generation end temperature. It is a figure for demonstrating the calculation method (calculation example 3) of the emitted-heat amount, the heat-generation start temperature, and the heat-generation end temperature. It is a figure for demonstrating the calculation method (calculation example 4) of the emitted-heat amount, the heat-generation start temperature, and the heat-generation end temperature. It is sectional drawing which shows the connection method of the circuit terminal concerning one Embodiment of this invention. It is a figure for demonstrating the measuring method of the curvature in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st board | substrate 1a 1st circuit electrode 2 2nd board | substrate 2a 2nd circuit electrode 3 Adhesive 4 Conductive particle 5 Heating and pressing head

Claims (7)

A circuit connecting material that is interposed between opposing circuit electrodes, heats and presses the opposing circuit electrodes, and electrically connects only the electrodes in the pressing direction, and includes the following components (1) to (4) A circuit connecting material containing.
(1) radical polymerizable substance (2) polymerization initiator that generates free radicals upon heating (3) epoxy resin (4) cationic polymerizable initiator   2. The calorific value of the remaining peaks excluding the peak at which the temperature at the top of the exothermic curve is 200 ° C. or higher in DSC measurement in the range of 0 ° C. to 300 ° C. is 60% or more of the total calorific value. Circuit connection material.   In DSC measurement in the range of 0 ° C. to 300 ° C., excluding the peak where the temperature at the top of the exothermic curve is 200 ° C. or higher, the exothermic start temperature of the remaining peak is 60 ° C. or higher, and the exothermic end temperature of that peak is 180 ° C. The circuit connection material according to claim 1, wherein:   The radically polymerizable substance (1) is a (meth) acrylate compound, and the (meth) acrylate equivalent of the (meth) acrylate compound is larger than the epoxy equivalent of the epoxy resin (3). The circuit connection material according to claim 1.   The circuit connection material according to claim 4, wherein the (meth) acrylate compound contains 6 or more ethylene oxide and / or propylene oxide in the skeleton, and has 2 or more (meth) acryloyl groups.   The first circuit member having the first connection terminal and the second circuit member having the second connection terminal are arranged to face the first connection terminal and the second connection terminal, and The circuit connection material according to any one of claims 1 to 5 is interposed between a first connection terminal and a second connection terminal arranged to face each other, and the first connection terminal and the second connection terminals arranged to face each other. A circuit terminal connection structure in which only the connection terminals are electrically connected. A first circuit member having a first connection terminal and a second circuit member having a second connection terminal are disposed so that the first connection terminal and the second connection terminal are opposed to each other, and the opposed arrangement is performed. The circuit connection material according to any one of claims 1 to 5 is interposed between the first connection terminal and the second connection terminal, and the first connection terminal and the second disposed opposite to each other by heating and pressing. Circuit terminal connection method for electrically connecting only the connection terminals.

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